Been playing around with RELAX NG XML Schemas (as opposed to W3C XML Schema Definitions). RELAX NG is a practical solution to the problems that are not solved by XSDs. RELAX NG is an OASIS standard being put forward for ISO standardisation and as such, there are many implementations. Point 3 and 4 below are intresting reads regarding XML+XSD schemas and the various issues with XSD.



(1) RELAX NG Compact Syntax Tutorial
(2) RELAX NG - Refinement of values
xsd:integer { minInclusive="5" maxExclusive="10" }
xsd:string { minLength="4" maxLength="17" }
xsd:string { pattern="[A-Z]\d[A-Z]\s+\d[A-Z]\d" }

(3) RELAX NG better than W3C XML Schemas
(4) RELAX NG vs W3C XML Schema
(5) RELAX NG Jing ANT